To have a meeting among participants not located in the same area, a number of technological systems are available. These systems may include videoconferencing, web conferencing or audio conferencing.
The most realistic substitute of real meetings is high-end videoconferencing systems. Conventional videoconferencing systems comprise a number of end-points communicating real-time video, audio and/or data streams over WAN, LAN and/or circuit switched networks. The end-points include one or more monitor(s), camera(s), microphone(s) and/or data capture device(s) and a codec, which encodes and decodes outgoing and incoming streams, respectively. In addition, a centralized source, known as a Multipoint Control Unit (MCU), is needed to link the multiple end-points together. The MCU performs this linking by receiving the multimedia signals (audio, video and/or data) from end-point terminals over point-to-point connections, processing the received signals, and retransmitting the processed signals to selected end-point terminals in the conference.
By using a videoconferencing system, a PowerPoint presentation or any other PC-presentation may for instance be presented while still being able to see and hear all the other participants.
Another common way of presenting multimedia content is to stream data to computers through a web interface. The data stream may be transmitted in real-time, or a play back of an archived content through a distribution device. Conventional streaming data is adapted for storage and distribution, and therefore the multimedia content is represented in a different format than for video conferencing. Hence, to allow for streaming and archiving of a conventional video conference, a system for converting the multimedia data is needed. One example of such system is described in the following.
A distribution device is preferably provided with a network interface for connecting the device to a computer network, audio/video and presentation data interfaces for receiving conference content, a file conversion engine for converting presentation content into a standard image format for distribution, and a stream encoder for encoding the content into streaming format for distribution. The distribution device is further equipped with a stream server for transmitting the encoded audio/video content and a web server for transmitting web pages and converted presentation content to terminals located at nodes of the network. The distribution device is also adapted to create an archive file consisting of the encoded stream data, residing at local storage media or in a server/database, to enable later on-demand distribution to requesters at remote terminals over the computer network.
According to a typical mode of operation, the conference is initiated by including the distribution device as a participant in the conference. A viewer at a remote terminal can access a conference by directing a conventional web browser to an URL (Uniform Resource Locator) associated with the distribution device. After completion of validation data interchanges between the viewer and the distribution device, the viewer is able to view the personal interchange, i.e. the conversation and associated behaviour, occurring between the participants at the conference presenter site, as well as view the presentation content being presented at the conference site. The multimedia content is viewed in a multiple-window user interface through the viewer web browser, with the audio/video content presented by a streaming media player, and the presentation content displayed in a separate window. When requested by the head of the conference or by the conference management system, encoded stream data is stored in a server as an identifiable file.
The combination of streaming and conferencing technology opens up new possibilities for storing and documenting meetings, presentations, lectures and other forms of conversation and deliveries. However, this will be of limited value if not being able to search in the content of archived stream data. The only known way to enable search in archived stream data is to manually associate metadata to the stored files. However, this requires a lot of manual work, and it does not guarantee that the metadata correspond correctly to the stream data.